National Research Council of Italy

Institute of Biosciences and BioResources

DISBA logo CNR logo
IBBR publication #1642

Polyploidization alters constitutive content of volatile organic compounds (VOC) and improves membrane stability under water deficit in Volkamer lemon (Citrus limonia Osb.) leaves

Vieira DD, Emiliani G, Michelozzi M, Centritto M, Luro F, Morillon R, Loreto F, Gesteira A, Maserti B

Environmental and Experimental Botany 126: 1-9. (2016)
doi: 10.1016/j.envexpbot.2016.02.010

In Citrus species chromosome doubling naturally occurs in somatic embryos and doubled diploid plants often show better adaptation to adverse environmental condition. To understand the molecular determinants of stress acclimation, we examined the response to water deficit in diploid (2VL) and doubled diploid (4VL) seedlings of Volkamer lemon (Citrus limonia Osb.) assessing the profile of constitutive volatile organic compound (VOC) in control and stressed conditions. Physiological parameters and leaf volatile compound profiles were measured during water deficit and 24 h after rehydration of plants to field capacity. Net photosynthesis and stomatal conductance were reduced in water stressed leaves, with no significant differences between 2VL and 4VL plants. Malondialdehyde concentration, a marker of lipid peroxidation of cellular membranes, was significantly more higher in stressed 2VL leaves than in 4VL. The blend of constitutive VOC was different in control leaves being oxygenated sesquiterpenoids more abundant in 2VL leaves, and monoterpenoids more abundant in 4VL leaves. Water deficit did not stimulate biosynthesis of terpenoids, whereas accumulation of trans- 2 hexenal, a green leaf volatile (GLV) synthesized after membrane denaturation, was observed in stressed leaves of 2VL leaves, but notin 4VL leaves. Semiquantitative PCR showed an increase of the expression of HPL, the gene encoding for hydroperoxidase lyase which catalyzes 2-hexenal formation, only in 2VL plants. The expression of the putative dehydration transcription factor DREB2A was also observed only in 2VL water stressed plants. This work shows that level of ploidy may alter constitutive content of GLV by Citrus, therefore likely affecting plants capacity of protection and interaction with other organisms. Whereas diploid and double diploid plants showed similar physiological responses to water deficit, a biochemical marker indicated that membranes of double diploid leaves were more resistant to the stress. These results provide intriguing insights into the regulation of terpenoids and oxylipins pathways as a function of polyploidization in a non-model plant species. ã 2016 Els

IBBR Authors:
Actions
Select by Year
Select by Type
Select by Author
*
*
*
*
Istituto di Bioscienze e Biorisorse (IBBR/CNR)
Via G. Amendola 165/A, I-70126 Bari (Italy)
Copyright © 2012-2024. All Rights Reserved.